/*
 * Copyright 2023 Google LLC
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef GrTextureGenerator_DEFINED
#define GrTextureGenerator_DEFINED

#include "include/core/SkImageGenerator.h"
#include "include/gpu/GrTypes.h"
#include "include/private/base/SkAPI.h"

#include <cstdint>

class GrRecordingContext;
class GrSurfaceProxyView;
enum class GrImageTexGenPolicy : int;
namespace skgpu {
enum class Mipmapped : bool;
}
struct SkImageInfo;

class SK_API GrTextureGenerator : public SkImageGenerator {
public:
    bool isTextureGenerator() const final
    {
        return true;
    }

    /* *
     * If the generator can natively/efficiently return its pixels as a GPU image (backed by a
     * texture) this will return that image. If not, this will return NULL.
     *
     * Regarding the GrRecordingContext parameter:
     *
     * It must be non-NULL. The generator should only succeed if:
     * - its internal context is the same
     * - it can somehow convert its texture into one that is valid for the provided context.
     *
     * If the mipmapped parameter is kYes, the generator should try to create a TextureProxy that
     * at least has the mip levels allocated and the base layer filled in. If this is not possible,
     * the generator is allowed to return a non mipped proxy, but this will have some additional
     * overhead in later allocating mips and copying of the base layer.
     *
     * GrImageTexGenPolicy determines whether or not a new texture must be created (and its budget
     * status) or whether this may (but is not required to) return a pre-existing texture that is
     * retained by the generator (kDraw).
     */
    GrSurfaceProxyView generateTexture(GrRecordingContext *, const SkImageInfo &info, skgpu::Mipmapped mipmapped,
        GrImageTexGenPolicy);

    // External clients should override GrExternalTextureGenerator instead of trying to implement
    // this (which uses private Skia types)
    virtual GrSurfaceProxyView onGenerateTexture(GrRecordingContext *, const SkImageInfo &, skgpu::Mipmapped,
        GrImageTexGenPolicy) = 0;

    // Most internal SkImageGenerators produce textures and views that use kTopLeft_GrSurfaceOrigin.
    // If the generator may produce textures with different origins (e.g.
    // GrAHardwareBufferImageGenerator) it should override this function to return the correct
    // origin. Implementations should be thread-safe.
    virtual GrSurfaceOrigin origin() const
    {
        return kTopLeft_GrSurfaceOrigin;
    }

protected:
    GrTextureGenerator(const SkImageInfo &info, uint32_t uniqueId = kNeedNewImageUniqueID);
};

#endif // GrTextureGenerator_DEFINED
